On August 26, 2019 7:11:22 AM PDT, Cy Schubert <cy.schub...@cschubert.com> wrote: >In message <6c6bf3a4-dc07-4d9a-9a5f-fa075bf53...@cschubert.com>, Cy >Schubert wr >ites: >> On August 24, 2019 10:13:15 PM PDT, Mateusz Guzik <m...@freebsd.org> >wrote: >> >Author: mjg >> >Date: Sun Aug 25 05:13:15 2019 >> >New Revision: 351472 >> >URL: https://svnweb.freebsd.org/changeset/base/351472 >> > >> >Log: >> > nullfs: reduce areas protected by vnode interlock >> > >> >Some places only take the interlock to hold the vnode, which was a >> >requiremnt >> >before they started being manipulated with atomics. Use the newly >> >introduced >> > vholdnz to bump the count. >> > >> > Reviewed by: kib >> > Tested by: pho >> > Sponsored by: The FreeBSD Foundation >> > Differential Revision: https://reviews.freebsd.org/D21358 >> > >> >Modified: >> > head/sys/fs/nullfs/null_vnops.c >> > >> >Modified: head/sys/fs/nullfs/null_vnops.c >> >>============================================================================ >> == >> >--- head/sys/fs/nullfs/null_vnops.c Sun Aug 25 05:11:43 2019 (r35147 >> 1) >> >+++ head/sys/fs/nullfs/null_vnops.c Sun Aug 25 05:13:15 2019 (r35147 >> 2) >> >@@ -668,7 +668,7 @@ null_lock(struct vop_lock1_args *ap) >> > * We prevent it from being recycled by holding the vnode >> > * here. >> > */ >> >- vholdl(lvp); >> >+ vholdnz(lvp); >> > error = VOP_LOCK(lvp, flags); >> > >> > /* >> >@@ -710,31 +710,16 @@ static int >> > null_unlock(struct vop_unlock_args *ap) >> > { >> > struct vnode *vp = ap->a_vp; >> >- int flags = ap->a_flags; >> >- int mtxlkflag = 0; >> > struct null_node *nn; >> > struct vnode *lvp; >> > int error; >> > >> >- if ((flags & LK_INTERLOCK) != 0) >> >- mtxlkflag = 1; >> >- else if (mtx_owned(VI_MTX(vp)) == 0) { >> >- VI_LOCK(vp); >> >- mtxlkflag = 2; >> >- } >> > nn = VTONULL(vp); >> > if (nn != NULL && (lvp = NULLVPTOLOWERVP(vp)) != NULL) { >> >- VI_LOCK_FLAGS(lvp, MTX_DUPOK); >> >- flags |= LK_INTERLOCK; >> >- vholdl(lvp); >> >- VI_UNLOCK(vp); >> >- error = VOP_UNLOCK(lvp, flags); >> >+ vholdnz(lvp); >> >+ error = VOP_UNLOCK(lvp, 0); >> > vdrop(lvp); >> >- if (mtxlkflag == 0) >> >- VI_LOCK(vp); >> > } else { >> >- if (mtxlkflag == 2) >> >- VI_UNLOCK(vp); >> > error = vop_stdunlock(ap); >> > } >> > >> >@@ -845,10 +830,8 @@ null_getwritemount(struct >vop_getwritemount_args >> >*ap) >> > VI_LOCK(vp); >> > xp = VTONULL(vp); >> > if (xp && (lowervp = xp->null_lowervp)) { >> >- VI_LOCK_FLAGS(lowervp, MTX_DUPOK); >> >+ vholdnz(lowervp); >> > VI_UNLOCK(vp); >> >- vholdl(lowervp); >> >- VI_UNLOCK(lowervp); >> > VOP_GETWRITEMOUNT(lowervp, ap->a_mpp); >> > vdrop(lowervp); >> > } else { >> >> Hi mjg@, >> >> This causes trap 12 a few seconds after mountlate during boot. >Reverting this >> commit allowed it to boot. >> >> Sorry for no backtrace. I managed to >> revert and test just prior to rushing out to catch the bus, with no >time to >> craft a proper email. I'll post the backtrace when I arrive at work. > >Hi mjg@, > >The gory details below. Don't be fooled by the panic when yppasswd is >started. I was able to reproduce this panic in single user by simply >mounting and using a nullfs. > >kernel trap 12 with interrupts disabled > > >Fatal trap 12: page fault while in kernel mode >cpuid = 0; apic id = 00 >fault virtual address = 0xc >fault code = supervisor read data, page not present >instruction pointer = 0x20:0xffffffff806f0633 >stack pointer = 0x28:0xfffffe004b3fa7c0 >frame pointer = 0x28:0xfffffe004b3fa7e0 >code segment = base 0x0, limit 0xfffff, type 0x1b > = DPL 0, pres 1, long 1, def32 0, gran 1 >processor eflags = resume, IOPL = 0 >current process = 26 (syncer) >trap number = 12 >panic: page fault >cpuid = 0 >time = 1566821203 >KDB: stack backtrace: >db_trace_self_wrapper() at db_trace_self_wrapper+0x2b/frame >0xfffffe004b3fa470 >vpanic() at vpanic+0x19d/frame 0xfffffe004b3fa4c0 >panic() at panic+0x43/frame 0xfffffe004b3fa520 >trap_fatal() at trap_fatal+0x39c/frame 0xfffffe004b3fa580 >trap_pfault() at trap_pfault+0x49/frame 0xfffffe004b3fa5e0 >trap() at trap+0x29d/frame 0xfffffe004b3fa6f0 >calltrap() at calltrap+0x8/frame 0xfffffe004b3fa6f0 >--- trap 0xc, rip = 0xffffffff806f0633, rsp = 0xfffffe004b3fa7c0, rbp = >0xfffffe004b3fa7e0 --- >propagate_priority() at propagate_priority+0x153/frame >0xfffffe004b3fa7e0 >turnstile_wait() at turnstile_wait+0x32b/frame 0xfffffe004b3fa830 >__mtx_lock_sleep() at __mtx_lock_sleep+0x191/frame 0xfffffe004b3fa8c0 >mnt_vnode_next_active() at mnt_vnode_next_active+0x2cb/frame >0xfffffe004b3fa920 >vfs_msync() at vfs_msync+0x266/frame 0xfffffe004b3fa980 >sync_fsync() at sync_fsync+0xe6/frame 0xfffffe004b3fa9c0 >VOP_FSYNC_APV() at VOP_FSYNC_APV+0x56/frame 0xfffffe004b3fa9e0 >sched_sync() at sched_sync+0x379/frame 0xfffffe004b3faa70 >fork_exit() at fork_exit+0x83/frame 0xfffffe004b3faab0 >fork_trampoline() at fork_trampoline+0xe/frame 0xfffffe004b3faab0 >--- trap 0, rip = 0, rsp = 0, rbp = 0 --- >Uptime: 3m25s >Dumping 921 out of 7974 >MB:..2%..11%..21%..32%..42%..51%..61%..72%..82%..91% > >__curthread () at /opt/src/svn-current/sys/amd64/include/pcpu.h:246 >246 __asm("movq %%gs:%P1,%0" : "=r" (td) : "n" >(OFFSETOF_CURTHREAD)); >(kgdb) #0 __curthread () at >/opt/src/svn-current/sys/amd64/include/pcpu.h:246 >#1 doadump (textdump=1) at >/opt/src/svn-current/sys/kern/kern_shutdown.c:392 >#2 0xffffffff8068aead in kern_reboot (howto=260) > at /opt/src/svn-current/sys/kern/kern_shutdown.c:479 >#3 0xffffffff8068b369 in vpanic (fmt=<optimized out>, ap=<optimized >out>) > at /opt/src/svn-current/sys/kern/kern_shutdown.c:905 >#4 0xffffffff8068b163 in panic (fmt=<unavailable>) > at /opt/src/svn-current/sys/kern/kern_shutdown.c:832 >#5 0xffffffff80a11c2c in trap_fatal (frame=0xfffffe004b3fa700, eva=12) > at /opt/src/svn-current/sys/amd64/amd64/trap.c:943 >#6 0xffffffff80a11c79 in trap_pfault (frame=0xfffffe004b3fa700, >usermode=0) > at /opt/src/svn-current/sys/amd64/amd64/trap.c:767 >#7 0xffffffff80a1126d in trap (frame=0xfffffe004b3fa700) > at /opt/src/svn-current/sys/amd64/amd64/trap.c:443 >#8 <signal handler called> >#9 propagate_priority (td=0xfffff8003e43b000) > at /opt/src/svn-current/sys/kern/subr_turnstile.c:279 >#10 0xffffffff806f13db in turnstile_wait (ts=0xfffff8000258a780, > owner=<optimized out>, queue=-512) > at /opt/src/svn-current/sys/kern/subr_turnstile.c:785 >#11 0xffffffff80669271 in __mtx_lock_sleep (c=0xfffff80132e4ebf0, > v=<optimized out>) at /opt/src/svn-current/sys/kern/kern_mutex.c:654 >#12 0xffffffff80767b1b in mnt_vnode_next_active_relock ( > mvp=0xfffff80002449800, mp=0xfffff80132d1e000, vp=0xfffff80132e4eb40) > at /opt/src/svn-current/sys/kern/vfs_subr.c:5590 >#13 mnt_vnode_next_active (mvp=<optimized out>, mp=0xfffff80132d1e000) > at /opt/src/svn-current/sys/kern/vfs_subr.c:5649 >#14 0xffffffff80766206 in __mnt_vnode_next_active >(mvp=0xfffff80002449800, > mp=<optimized out>) at /opt/src/svn-current/sys/kern/vfs_subr.c:5682 >#15 vfs_msync (mp=0xfffff80132d1e000, flags=2) > at /opt/src/svn-current/sys/kern/vfs_subr.c:4238 >#16 0xffffffff8076b4a6 in sync_fsync (ap=<optimized out>) > at /opt/src/svn-current/sys/kern/vfs_subr.c:4468 >#17 0xffffffff80a7be46 in VOP_FSYNC_APV ( > vop=0xffffffff80cb4120 <sync_vnodeops>, a=0xfffffe004b3faa08) > at vnode_if.c:1312 >#18 0xffffffff80769319 in VOP_FSYNC (vp=<optimized out>, waitfor=3, > td=0xfffff800061dc5a0) at ./vnode_if.h:549 >#19 sync_vnode (bo=<optimized out>, td=0xfffff800061dc5a0, > slp=<optimized out>) at /opt/src/svn-current/sys/kern/vfs_subr.c:2316 >#20 sched_sync () at /opt/src/svn-current/sys/kern/vfs_subr.c:2418 >#21 0xffffffff80647e33 in fork_exit (callout=0xffffffff80768fa0 ><sched_sync>, > arg=0x0, frame=0xfffffe004b3faac0) > at /opt/src/svn-current/sys/kern/kern_fork.c:1045 >#22 <signal handler called> > > >dmesg output: > >Updating motd:. >Mounting late filesystems:. >Starting nscd. >Security policy loaded: MAC/ntpd (mac_ntpd) >Starting ntpd. >Starting yppasswdd. >kernel trap 12 with interrupts disabled > > >Fatal trap 12: page fault while in kernel mode >cpuid = 0; apic id = 00 >fault virtual address = 0xc >fault code = supervisor read data, page not present >instruction pointer = 0x20:0xffffffff806f0633 >stack pointer = 0x28:0xfffffe004b7fa7c0 >frame pointer = 0x28:0xfffffe004b7fa7e0 >code segment = base 0x0, limit 0xfffff, type 0x1b > = DPL 0, pres 1, long 1, def32 0, gran 1 >processor eflags = resume, IOPL = 0 >current process = 26 (syncer) >trap number = 12 >panic: page fault >cpuid = 0 >time = 1566820700 >KDB: stack backtrace: >db_trace_self_wrapper() at db_trace_self_wrapper+0x2b/frame >0xfffffe004b7fa470 >vpanic() at vpanic+0x19d/frame 0xfffffe004b7fa4c0 >panic() at panic+0x43/frame 0xfffffe004b7fa520 >trap_fatal() at trap_fatal+0x39c/frame 0xfffffe004b7fa580 >trap_pfault() at trap_pfault+0x49/frame 0xfffffe004b7fa5e0 >trap() at trap+0x29d/frame 0xfffffe004b7fa6f0 >calltrap() at calltrap+0x8/frame 0xfffffe004b7fa6f0 >--- trap 0xc, rip = 0xffffffff806f0633, rsp = 0xfffffe004b7fa7c0, rbp = >0xfffffe004b7fa7e0 --- >propagate_priority() at propagate_priority+0x153/frame >0xfffffe004b7fa7e0 >turnstile_wait() at turnstile_wait+0x32b/frame 0xfffffe004b7fa830 >__mtx_lock_sleep() at __mtx_lock_sleep+0x191/frame 0xfffffe004b7fa8c0 >mnt_vnode_next_active() at mnt_vnode_next_active+0x2cb/frame >0xfffffe004b7fa920 >vfs_msync() at vfs_msync+0x266/frame 0xfffffe004b7fa980 >sync_fsync() at sync_fsync+0xe6/frame 0xfffffe004b7fa9c0 >--- trap 0, rip = 0, rsp = 0, rbp = 0 --- >Uptime: 1m38s >Dumping 810 out of 7974 >MB:..2%..12%..22%..32%..42%..52%..62%..72%..81%..91%---<<BOOT>>---
This may be a simple case of increasing the kernel stack. I'll try this at noon. -- Pardon the typos and autocorrect, small keyboard in use. Cheers, Cy Schubert <cy.schub...@cschubert.com> FreeBSD UNIX: <c...@freebsd.org> Web: http://www.FreeBSD.org The need of the many outweighs the greed of the few. _______________________________________________ svn-src-head@freebsd.org mailing list https://lists.freebsd.org/mailman/listinfo/svn-src-head To unsubscribe, send any mail to "svn-src-head-unsubscr...@freebsd.org"
